In December following, he first appeared in the sporting world as a swift runner. He had performed long journies beyond the power of any man living, which was attributed to his great strength and bottom; but it was generally supposed that he did not possess fleetness sufficient to enable him to cope with any of the first-rate runners. The KNOWING ONES, however were deceived; for Capt. Barclay proved, that even at a very short distance, he had few competitors. He started in Hyde Park to run a quarter of a mile against Mr. John Ward, and bets were two to one in favour of his antagonist. Ward took the lead, and kept it for the first three hundred yards. Capt. Barclay then beat up, and they ran the next hundred yards neck and neck. In the last forty, Ward lost ten yards; and Capt. Barclay accomplished the whole distance, four hundred and forty yards, in fifty-six seconds,--Mr. Fletcher Reid and the Hon. B. Craven, were the umpires. In March 1804, Capt. Barclay undertook, for a wager of two hundred guineas, to walk twenty-three miles in three hours. It was intended that he should start in Hertfordshire, and finish at the Royal Exchange, London. But unfortunately, on the day appointed he was taken ill, and consequently lost his stake. The sporting world were thus disappointed; and any odds would have been laid that he should have completed the task. On Thursday the 16th of August, Capt. Barclay, who was then a lieutenant in the 23d regiment of foot, and quartered at East Bourne in Suffolk, engaged to run two miles in twelve minutes. He accomplished this undertaking with apparent ease, in two seconds and a half within the time. The arduousness of the task was greatly increased by the excessive rain which had fallen during the two preceding days, and a high wind that blew in his face. He ran the first mile in five minutes. On the 18th of the following month, a match, to run one mile for one hundred guineas, was performed at East Bourne between Capt. Barclay and Capt. Marston of the 48th regiment. Both gentlemen were such celebrated pedestrians, that the race attracted some hundreds of spectators, and a great deal of money was sported. Capt. Marston being known by the regiment as a swift runner, found many to back him. They started at an early hour. Capt. Barclay suffered his competitor to take the lead, and keep it for a short distance, when he passed him, and continued a-head to the end of the race, which he accomplished in five minutes and seven seconds, notwithstanding the intense heat of the day. Mr. Fletcher Reid attended as the umpire. At the same place, Capt. Barclay ran a mile against John Ireland of Manchester, one of the swiftest runners in that quarter, on the 12th of October, for a bet of five hundred guineas. Ireland gave in at three-fourths of the mile; but Capt. Barclay performed the whole distance in four minutes and fifty seconds.